The depth of field (DoF) and aperture are important imaging control parameters. The depth of field usually means a depth scope in which clear imaging of an object can be acquired by a camera lens. Usually the imaging in the depth of field is clear, while the imaging out of the depth of field is relative blurred. The aperture size may affect the quantity of light through a lens aperture in unit time. By adjusting the aperture, the imaging parameters, such as the exposure time and depth of field, may be adjusted. For example, the degree of exposure may be increased by increasing the aperture, so that a higher shutter speed may be acquired, but the depth of field is relative shallow.